1. Technical Field
The present invention relates to: a light source device provided with a circuit board on which a LED is mounted; and a display device provided with this light source device.
2. Description of the Related Art
In a display device such a television set, a light source device is disposed on the rear side of a display part having, on the front side, a display surface displaying an image.
A light source device has, for example: a LED board having a plurality of LEDs mounted on one surface; a lens accommodating the LED and diffuses light emitted from the LED; and a lens cover that has a through hole into which the lens is inserted and that holds the lens on the LED board. Then, a reflecting layer reflecting the light diffused by the lens is provided in the lens cover (see, for example, Japanese Patent Laid-Open No. 2008-41546).
The lens has a semi-spherical shape of a smaller diameter than the through hole, protrudes outward from a transparent part inserted into the through hole and the periphery on the open side of the transparent part, and has a flange having a larger diameter than the through hole. Then, such a configuration is employed that when the lens cover is attached to the LED board with a plurality of male screws, the flange is pinched between the peripheral edge of the through hole in the lens cover and the LED board so that the lens is positioned and fixed.
Here, in a configuration that the lens cover positions and fixes the lens as described in Patent Document 1, when the lens cover is fabricated from a relatively thick sheet, the lens cover hardly deforms and hence positioning and fixing of the lens is achieved by using a relatively small number of male screws. Nevertheless, in flat-screen display devices such as a liquid crystal television set employing a light source device, the trends of price reduction, weight reduction, and thickness reduction are continuing. Thus, when the lens cover is fabricated from a relatively thick sheet, a problem is caused in the price reduction, weight reduction, and thickness reduction of the display device and hence this configuration is not preferable.
When the lens cover is fabricated from a relatively thin sheet, the lens cover in which a through hole corresponding to the lens is opened deforms easily. Thus, deformation such as warp of the lens cover is not suppressed unless the number of male screws is increased. This causes an increase in the number of components and an increase in the number of process steps of screwing the male screws, so as to cause a problem of cost increase. Further, when a relatively large number of LEDs are employed, a problem arises that the position of each lens disposed distant from the male screws easily becomes unstable.